The Dolphin Research Center in Marathon, Florida is where people can swim with the well cared-for marine mammals, but it's much more than that.  It's a rescue operation for not only dolphins, but sea turtles, manatees and other Florida Keys species.  When the dolphins aren't busy with that, or doing their research, they maintain an informative blog, where they post videos of themselves like this one.  Amazingly smart creatures.

(YouTube Link)

Seriously though, the DRC is top tier when it comes to places like this.  Here's a snip from Hannah's five star review on Yelp:

After an afternoon at this terrific research center, I learned more about dolphins than I ever thought I'd know. We came here as a group, with the BF and his parents. For $20 a person, you get admission, which allows you to walk through the center and watch the public shows. The place is very low key - it's obvious that all their money goes towards taking care of the dolphins,and not on frills.

Link (Photo: DRC)